50 th Annual Meeting Long Program

Transcription

1 50 th Annual Meeting Long Program November 2018 Furnace Creek, Death Valley National Park, California, USA Species in a bucket; recovery of Owens Pupfish, Fish Slough, 1969

2 Overview and Event Locations Date & Time Event Location Wednesday, 14 November :00-21:00 Registration and Presentation Loading Furnace Creek Visitor Center 18:00-20:30 Social Mixer The Oasis Room Thursday, 15 November :00-18:00 Registration and Presentation Loading Furnace Creek Visitor Center 08:30-09:00 Welcome Furnace Creek Visitor Center Auditorium 09:00-11:30 Lee Simons: Advocate for Desert Fishes Symposium Furnace Creek Visitor Center Auditorium 11:30-13:00 Lunch 11:30-13:00 Yaqui Catfish Meeting Furnace Creek Visitor Center Auditorium 13:00-16:00 Standing Between Life and Extinction: Book Preview Symposium Furnace Creek Visitor Center Auditorium 16:00-17:30 General Session I Furnace Creek Visitor Center Auditorium 17:45-19:45 Poster Session Furnace Creek Visitor Center Auditorium 19:45-21:45 Student Networking Session Furnace Creek Visitor Center Auditorium Friday, 16 November :30-12:00 General Session II Furnace Creek Visitor Center Auditorium 12:00-13:30 Lunch 13:30-17:00 General Session III Furnace Creek Visitor Center Auditorium 17:15-18:15 Business Meeting Furnace Creek Visitor Center Auditorium 19:15-21:15 Banquet The Date Grove Saturday 17 November :30-12:00 General Session IV Furnace Creek Visitor Center Auditorium 12:00-13:30 Lunch 13:30-17:00 General Session V Furnace Creek Visitor Center Auditorium Sunday 18 November :00-13:00 Field Trip Amargosa River

3 We thank our generous hosts: Cover artwork by Barbara Terkanian Events are in Furnace Creek Visitor Center Auditorium unless otherwise specified. Presenters, please load your presentation by 6:00 pm the day before your presentation. Student award presentations are highlighted in gray. Long Program Detail Wednesday, November 14th 16:00-21:00 Registration and Presentation Loading (Furnace Creek Visitor Center) 18:00-20:30 Social Mixer (The Oasis Room) Thursday, November 15th 08:00-18:00 Registration and Presentation Loading (Furnace Creek Visitor Center) 08:30-09:00 Welcome (Chairs: Phil Pister and Krissy Wilson) 09:00-11:30 Session 1: Lee Simons: Advocate for Desert Fishes Symposium (Chair: Leslie Fitzpatrick or Brandon Senger) 09:00 Remembrance of Dr. Lee H. Simons Gary Scoppettone 1, Dean A. Hendrickson 2, Jon Sjoberg 3, David Syzdek 4, Paul Barrett 5 (1-retired; 2-University of Texas at Austin, Biodiversity Collections, United States; 3-Nevada Department of Wildlife, United States; 4-Southern Nevada Water Authority, United States; 5-U.S. Fish and Wildlife Service (retired), United States). On the occasion of the 50th annual Desert Fishes Council meeting, this session is dedicated to Dr. Lee H. Simons, who devoted much of his adult life to the study and protection of native species and ecosystems. Dr. Simons is honored here today because he exemplified the spirit and soul of the Desert Fishes Council working together to protect and preserve our native species and natural ecosystems. As a positive force toward these goals, Dr. Simons spent a third of his natural resources career focused on the protection and recovery of federally listed endangered desert fishes in Arizona and Nevada. From

4 1985 to 1988 Lee worked for Arizona Game and Fish, much of that time focused on recovery activities of Gila topminnow. After earning his PhD at U.C. Davis and working in research, science education and natural resources, Dr. Simons renewed his work with desert fishes from As Senior Fish Biologist for the Las Vegas Office of the U. S. Fish and Wildlife Service, he concentrated on recovery actions for Devil s Hole Pupfish, Moapa Dace, and Pahranagat Roundtail Chub. Those of us who worked with Lee on endangered desert fish recovery appreciated his intellect, kind manner, leadership, infectious enthusiasm, and all his accomplishments. Remembrance of Dr. Simons s all too short, but stellar desert fish career will be briefly covered by four co-workers representing four different agencies. 09:15 Lee Simons a Carpenter of Convergence: Restoration Project Legacy for Southern Nevada Aquatic Species with Current Status Updates. Kevin Guadalupe (Nevada Department of Wildlife, United States) As the Environmental Services lead fish biologist for the United States Fish and Wildlife Service Southern Nevada Field Office, Lee was responsible for recovery of 12 listed fish species. His leadership and kindness at recovery team meetings consolidated agency leads, academics, and local shareholders to cooperate towards ongoing restoration and increasing population numbers. He gave expedient consultation on restoration projects for Pahrump Poolfish Empetrichthys latos, Ash Meadows National Wildlife Refuge, Devils Hole, and other listed fish species in the pluvial White River system while also getting in the mud to complete the work. Lee was instrumental in acquiring two national competitive funding opportunities through Cooperative Recovery Initiative (CRI) funding. The Muddy River CRI funding completed two new fish barriers, and hired two new temporary employees entirely devoted to the restoration and monitoring of the Muddy River system. Moapa Dace, Moapa coriacea Snorkel counts are currently four times greater than at the time of his arrival with Virgin River Chub, Gila seminuda existing in the upper Muddy River for the first time since pre non-native fish invasion. The Pahranagat Cooperative Recovery Initiative funding initiated a Pahranagat Roundtail Chub, Gila robusta jordani PIT tag monitoring program, stabilized the refuge population at Key Pittman, and developed a new refuge habitat at Cottonwood Spring. During the 2013 low count of 35 Devils Hole Pupfish, Cyprinodon diabolis Lee took charge to bring the multi-agency command team together. He would then praise the recovery response to others in his team. Non-natives removal projects and restoration projects are complete or ongoing in The Virgin River, Muddy River, Pahranagat, Ash Meadows, and at Pahrump Poolfish refuge populations, including a new refuge site initiated in 2018 as a result of his leadership. 09:30 The Direct Impacts of Non-Native Species on Pahrump Poolfish, Empetrichthys latos latos Brandon Paulson 1, Craig Stockwell 1 (1-NDSU, United States) Desert fishes that evolved in simple communities are hypothesized to be vulnerable to non-native species introductions. Such is the case for the Pahrump Poolfish, Empetrichthys latos latos, whose conservation has been frustrated by colonization of invasive species including both Red Swamp Crayfish, Procambarus clarkii, and Western

5 Mosquitofish, Gambusia affinis, in refuge habitats. We examined the direct effects of crayfish and mosquitofish on poolfish adult survivorship, and juvenile recruitment under semi-natural conditions in 300-gallon mesocosms. We found that allopatric poolfish populations had significantly higher adult survival (95.6%.03%) than when held in sympatry with crayfish (53.1%.16%; z = -3.2; p < 0.005) or when sympatric with crayfish and mosquitofish ( %; z = -2,98; p < 0.010). Crayfish had no effect on poolfish juvenile recruitment ( juveniles per adult) compared to juvenile recruitment for allopatric poolfish populations ( juveniles per adult; z=.6; p > 0.05). However, the combined effects of crayfish and mosquitofish led to significant declines in juvenile recruitment ( juveniles per adult; z = -2.79; p = 0.015). These results mimicked earlier experiments that showed severe impacts of mosquitofish on poolfish juvenile recruitment (Goodchild & Stockwell 2016, Trans. Am. Fish. Soc. 145 (2); ). Thus, our findings combined with earlier work may explain how poolfish have copersisted with crayfish for numerous years at the Corn Creek refuge, while the dual invasion of crayfish and mosquitofish was associated with a rapid population decline of the largest Pahrump poolfish refuge population at Spring Mountain Ranch. 09:45 Antipredator Club Cell Evaluation in Insular Fishes Madison Snider 1, Brian Wisenden 2, Craig Stockwell 1 (1-North Dakota State University, United States; 2- Minnesota State University-Moorhead, United States) Species that evolve in habitats with limited predation are predicted to have reduced investment in antipredator traits, such as the production and detection of chemical alarm cues. Our study focused on epithelial club cells, which are presumed to contain injuryreleased alarm cues and are present in numerous fish taxa. This evaluation was carried out on four desert fishes in the Cyprinodontiformes; Pahrump Poolfish, Empetrichthys latos latos, White River Springfish, Crenichthys baileyi, Amargosa Pupfish, Cyprinodon nevadensis, and White Sands Pupfish, Cyprinodon tularosa. We also sampled three cyprinid species: Hot Creek Valley Tui Chub, Suphateles bicolor ssp., and two noninsular species, Fathead Minnow, Pimephales promelas, and Zebrafish, Danio rerio. Club cell densities per mm2 of epithelial tissue differed significantly among species (X2 = 91.81, df = 6, p < ), and pairwise comparisons revealed no differences among Cyprinds or among Cyprinodontiformes. As expected, Fathead Minnows and Zebrafish displayed relatively high densities of club cells (446.5 ± 100.3; ± 51.3; mean ± SE, respectively). By contrast, mean club cell densities were low for Pahrump poolfish (17.1 ± 8.5), White Sands pupfish (17.1 ± 9.0), Amargosa Pupfish (1.0 ± 0.6), and White River Springfish (0.0 ± 0.0). In comparison, however, the Hot Creek Valley Tui Chub, a desert cyprinid, displayed club cell densities similar to non-insular cyprinids sampled (137.9 ± 56.3). Thus, phylogeny, and not locality or history of predation, may be the primary driver for expression of club cells and antipredator behaviors present in populations. 10:00 Recovery on Private Land Pahranagat Roundtail Chub Progress Christiana Manville 1, James Harter 1, Cody Anderson 2 (1- U.S. Fish and Wildlife Service, United States; 2-Great Basin Institute, United States) The Pahranagat Roundtail Chub, Gila robusta jordani, is a federally endangered species whose native habitat resides entirely within an active cattle ranch of the Pahranagat

6 Valley, Lincoln County, Nevada. The current distribution consists of 2.2 miles of stream channel and 1.5 miles of a cement-lined irrigation ditch. Working through the USFWS s Partners for Fish and Wildlife Program, we have developed a working relationship with the landowner, allowing us to implement five restoration projects over the last nine years. Some projects directly benefit chub, while others help the landowner manage resource concerns that otherwise hinder the cattle operation. Since 2014, we have intensified research in the field, including implementing seasonal snorkeling surveys, mark-recapture studies of adults, larval fish monitoring, and evaluating fish habitat. Important results of these studies lead to the discovery that juvenile fish are lost to the system during the irrigation season, which has led to yearly salvaging of juveniles. Through these studies we significantly improved our understanding of this species and needs for future recovery efforts. This conservation program was made possible by funds from the USFWS s Cooperative Recovery Initiative (CRI) program. Finally, we acknowledge Lee Simons for his leadership in writing the CRI Proposal in 2013, developing the monitoring program, and for his strong support of conservation on private lands. 10:15 History and Status of Fish Conservation on the Upper Muddy River, Nevada Michael R. Schwemm 1, Brandon L. Senger 2, David J. Syzdek 3 (1- United States Fish and Wildlife Service, United States; 2- Nevada Department of Wildlife, United States; 3- Southern Nevada Water Authority, United States) The headwaters of the Muddy River, Clark Co., Nevada, is formed by discharge of numerous thermal springs and seeps, and the sole habitat of the endangered cyprinid, Moapa coriacea. The species was common when described, but early reports indicate its decline in the middle 1960s, a result of the combined threats of habitat modification and exotic invasive species. When the USFWS acquired several springs in 1979 to establish the Moapa Valley National Wildlife Refuge, much the habitat had been converted to modified channels and swimming pools used for aquatic recreation. The process to return the habitat to natural flowing channels and reduce non-native fishes is ongoing, and a story of gradual success. Here, we review the history of research, major management actions, and the recovery program that established partnerships central for the recovery of habitat and species. Particularly noteworthy for the recent accomplishments in the upper Muddy River is the role of biologist Lee Simons (USFWS, Las Vegas). His leadership provided the coordination responsible to direct and fund an extensive series of fish barrier construction projects, monitoring, salvage operations and stream renovation efforts. Today, the working group and partnerships enhanced by Lee s work continue to benefit the resource. 10:30 Ten Years of Restoration Projects for the Endangered Moapa Dace, Moapa coriacea at the Warm Springs Natural Area, Clark County, Nevada David Syzdek (Southern Nevada Water Authority, United States) The Moapa Warm Springs in Southern Nevada is a regional spring complex that form the headwaters of the Muddy River. These thermal springs, and associated streams, are habitat for an endemic suite of thermophilic aquatic species that includes the federallyendangered Moapa Dace (Moapa coriacea). Currently, the Southern Nevada Water Authority (SNWA) and stakeholders are undertaking recovery actions for the Moapa dace

7 and its habitat. These include construction of fish barriers, reduction in or removal of non-native and invasive species, riparian and aquatic habitat restoration, and development of an ecological model for the Moapa Dace. To facilitate recovery of the dace and other native species, SNWA purchased the 1,218-acre Warm Springs Ranch in September 2007 and designated it the Warm Springs Natural Area for conservation and environmental stewardship purposes. In 2008, Moapa Dace numbers suddenly declined to a record low of 459 individuals. Working with the US Fish and Wildlife Service (USFWS), Nevada Department of Wildlife (NDOW), and other stakeholders and researchers, SNWA is conducting stream restoration work and intensive habitat improvements to reverse the population s decline. Following the February 2008 nadir, dace numbers recovered somewhat but have yet to reach recovery levels. NDOW and SNWA has successfully treated the Upper Muddy River with rotenone to control the invasive and predatory Blue Tilapia (Oreochromis aureus). Furthermore, stream restoration and clearing of dense stands of invasive tamarisk (Tamarix spp.) and Fan Palm (Washingtonia filifera), is facilitating the reestablishment of native riparian vegetation, providing prevention of future wildfires, and continued improvement in Moapa dace numbers. In 2015, a removable fish barrier was opened which allows this fish access to its entire historical range. Moapa Dace numbers are currently stable and work continues to improve dace habitat, improve stream connectivity, and to monitor for invasive species. 10:45 Virgin River Long-Term Fish Community Monitoring Ron Kegerries 1, Brandon Albrecht 1, Harrison Mohn 1, Ron Rogers 1 Aaron Ambos 2 (1- BIO-WEST, Inc., United States; 2-Southern Nevada Water Authority, United States) From 1993 through 2017, BIO-WEST, Inc., with funding and support from various agencies, has monitored the lower Virgin River to assess the long-term fish community dynamics and the success of stocking efforts to establish and enhance Woundfin, Plagopterus argentissimus populations. Native fish relative abundance increased in the upper study reaches following flood events, while nonnative fish abundance declined during these post-flood periods. Reaches above the Bunkerville Diversion are still considered the source of all native fishes within the lower Virgin River. A historical comparison of both native and nonnative fish species captured in the lower Virgin River since 1998 shows species composition to be similar across years indicating that positive trends associated with flooding are short-lived. Long-term catch rate analysis for the lower Virgin River show that native fish abundance has not significantly changed, but nonnative fish abundance has declined significantly in the last two decades. A similar analysis of habitat shows little variation in habitat types, substrate, or cover present at sampling locations within the study area. This monitoring yields a long-term perspective to assess fish populations within the lower Virgin River by providing Virgin River Chub, Gila seminuda population estimates, and provide a holistic understanding of the fish community in anticipation of future nonnative fish species removal. Consistent data collection will continue to be important in monitoring the rare fishes of the lower Virgin

8 River and update recovery goals, particularly given the growing water demand in the region. 11:00 Devils Hole and the Legacy of Lee Simons: Kevin P. Wilson 1, Jeffry A. Goldstein 1, Ambre L. Chaudoin 1, John G. Wullschleger 2, Brandon L. Senger 3, Michael R. Schwemm 4, Olin G. Feuerbacher 4, Corey W. Lee 4, Javier Linares-Casenave 4, Jon C. Sjoberg 3 (1- Death Valley National Park, United States; 2-Water Resources Division, National Park Service, United States; 3-Nevada Department of Wildlife, United States; 4- US Fish and Wildlife Service, United States) Devils Hole has a history of conservation and recovery efforts dating back to the late 1940s. Since this time several individuals have played leading roles in keeping the iconic Devils Hole Pupfish Cyprinodon diabolis from becoming extinct. One such person was Dr. Lee Simons, a naturalist and desert fishes specialist, who during his tenure at the US Fish and Wildlife Service s Las Vegas office significantly influenced management decisions. Lee was an integral part of the Devils Hole pupfish team for five years. During this time, Lee witnessed the species decline to the lowest count on record of 35 observable pupfish in the spring of 2013 and increase to one of the highest counts in the last 10 years: 131 fish in fall Lee was instrumental in developing a captive propagation effort entitled Recovery and Husbandry of Devils Hole Pupfish Eggs from Devils Hole that is still in use today, and the guiding document to establish the refuge population at Ash Meadows. Lee will always be remembered for his critical thinking, camaraderie, and contributions of experimental design to the recovery teams on which he served. Even though Lee s time involved with Devils Hole was too brief, his efforts afforded lasting impacts on how managing agencies address recovery efforts in the future. P.S. Don t forget your knee pads! 11:15 Comparative Study of Microbial Biogeochemistry of Devils Hole and Ash Meadows Fish Conservation Facility Duane Moser 1, Joshua Sackett 1, Brittany Kruger 1, Scott Hamilton-Brehm 2 (1-Desert Research Institute, United States; 2-Southern Illinois University Carbondale, United States) Devils Hole is a tectonic cavern partially filled with deeply sourced groundwater from the Death Valley Regional Flow System (DVRFS). A single skylight in this vast underground system is the sole natural habitat for the critically endangered Devils Hole Pupfish, Cyprinodon diabolis. In Devils Hole, this fish survives under conditions (e.g. high temperatures and low dissolved oxygen concentrations) that would be lethal to most fish. The water of Devils Hole is highly oligotrophic, with extremely low productivity and organic carbon and nutrient concentrations. Like most cave-dominated systems, with the possible exception of the summer when direct sunlight reaches the water surface, the foundations of the food web in Devils Hole are primarily microbial. In the mid-2010s, the Ash Meadows Fish Conservation Facility (AMFCF), a full-scale replica of the uppermost 6.7 m of Devils Hole, was constructed by management agencies to establish a backup population of C. diabolis. To gain a more predictive understanding of the capacity of these unique paired natural and manmade environments to support fish, we evaluated their physical parameters and chemistry in combination with next-generation DNA

9 sequencing of planktonic and benthic bacterial and archaeal communities (16S rrna gene libraries). Major ion concentrations were consistent between the two systems, but water temperature and dissolved oxygen dynamics differed. Bioavailable nitrogen (primarily nitrate) was 5x lower in AMFCF. Devils Hole and AMFCF nitrogen:phosphorus molar ratios were 107:1 and 22:1, indicative of different nutrient control mechanisms. Both sites possess extraordinarily high microbial diversity, with over 40 prokaryotic phyla represented at each; with 37 shared between them and nearly half deriving from candidate phyla so-called microbial dark matter lineages. The abundance and composition of predicted photosynthetic primary producers (Cyanobacteria) was markedly different between sites: Devils Hole planktonic and sediment communities were dominated by large and visually conspicuous Oscillatoria spp. (13.2% mean relative abundance), which proved virtually undetectable in AMFCF. Conversely, AMFCF was dominated by a predicted heterotroph from the Verrucomicrobiaceae family (31.7%); which was comparatively rare (<2.4%) in Devils Hole. We propose that the paucity of bioavailable nitrogen in AMFCF, perhaps resulting from physical isolation from allochthonous environmental inputs, is reflected in the microbial assemblage disparity, influences biogeochemical cycling of other dissolved constituents, and may ultimately impact survivorship and recruitment of refuge populations of the Devils Hole pupfish. This work was dedicated to Lee Simons in a recent publication in PLOS One (Sackett, et al (3):e ). Our project was in large measure inspired by conversations with Dr. Simons, who contributed to both its conceptual design and provided insightful comments during preparation of the manuscript. His advocacy and friendship will be missed. 11:30-13:00 Lunch (on your own) 11:30-13:00 Yaqui Catfish Meeting (auditorium or adjacent patio) 13:00-16:15 Session 2: Standing Between Life and Extinction: Book Preview Symposium (Chair: David Propst) 13:00 The Next Chapter in the Battle Against Extinction Jack Williams 1, David Propst 2 (1-Trout Unlimited, United States; 2-University of New Mexico, United States) Water was a critical fuel for economic and population growth in the post-world War II North American West and its appropriation for human use brought new challenges to aquatic organisms that had evolved in harsh environments but were little prepared for extensive alteration of fragile aquatic habitats. At that time, neither the general public nor natural resource agencies had much regard for native fish species if they had no immediate and tangible worth to humans. But an increasing awareness by resource managers and academics of the plight of this vanishing fauna spawned the Desert Fishes Council in With passage of the Endangered Species Act in 1973, additional impetus for conservation of native aquatic organisms was provided. So began The Battle Against Extinction, a seminal book published in 1991 that chronicled progress and issues in aridland native fish conservation. Since then, new technologies and evolving strategies

10 provide new opportunities, but climate change exacerbates lingering threats. Now we launch a new effort to examine the ecology, policies and politics of desert fish conservation. As W.L. Minckley and Jim Deacon noted, it is not a lack of scientific expertise that prevents progress in conservation, rather, it is the lack of will by society to implement needed actions. The fate of many arid-land aquatic species and ecosystems now hangs in the balance. 13:15 Reflections on Some Good Friends: the Pioneers of the Desert Fishes Council Phil Pister (Desert Fishes Council, United States) The battle to save desert fishes has been fortunate to have some of the most dedicated and thoughtful advocates for conservation. Today, I will reflect on the pioneers of the Desert Fishes Council: Carl Hubbs, Bob Miller, Salvador Contreras-Balderas, W.L. Minckley, Jim Deacon, Clark Hubbs, and Bob Behnke. Biographies of these seven, as well as one for myself, are included in the upcoming book Standing Between Life and Extinction. Join me for some great times with these giants of desert fish conservation. 13:30 Mining Hidden Waters: Groundwater Depletion, Aquatic Habitat Degradation and Loss of Fish Diversity in the Chihuahuan Desert Ecoregion of Texas Gary Garrett 1, Megan Bean 2, Robert Edwards 1, Dean Hendrickson 1 (1-The University of Texas at Austin, United States; 2- Texas Parks and Wildlife Department, United States) Desert ecosystems are particularly susceptible to anthropogenic influences. This is especially true where limited water resources can be impaired by excessive water mining and concomitant depletion of aquifers. Herein, the decline of aquatic habitats throughout the Chihuahuan Desert of Texas is discussed and observations on relationships among declining aquifer levels, aquatic habitat degradation, and status of native fishes are presented. Examples from the Big Bend reach of the Rio Grande, Balmorhea Springs Complex, Pecos River, and Devils River reveal a decline in distribution and abundance of native fishes. Ongoing and impending land-use practices and increased demands on groundwater and surface water resources point to future reductions. However, activities are underway that represent a source of optimism for conservation of aquatic habitats and native fishes in the region. Native Fish Conservation Areas are being established to enhance management of desert ecosystems to restore and maintain functional watersheds, conserve aquatic habitats, and support populations of native fishes. Increased landowner awareness of the value of cooperative conservation of aquatic resources and their inclusion in management decisions are critically important, particularly in Texas where the majority of land is privately owned. Ultimately, archaic Texas water laws need revision and reformulation if desert aquatic systems are to be restored and preserved. 13:45 The Exotic Dilemma: Lessons Learned from Efforts to Recover Native Colorado River Basin Fishes Brandon Albrecht 1, Ron Kegerries 1, Ron Rogers 1, Paul Holden 1 (1-BIO-WEST, Inc., United States) Native fishes of desert aquatic ecosystems have been dramatically impacted by nonnative species. Over time, habitat modification and degradation have set the stage for the influx

11 of many nonnative taxa. Traditionally, nonnative fish control has meant attempting to eliminate every individual nonnative from the habitat of interest. In larger systems, complete elimination has proven impossible, and managers have sought ways for nonnative and native species to coexist or to reduce the stress of nonnative taxa on native species. This paper is the result of a chapter contribution to the new book, Standing Between Life and Extinction, and describes the nonnative fish dilemma, lessons learned, and possible pathways for remediation while providing several examples from the Colorado River basin. We suggest that habitat complexity and more natural flow regimes can help enable native fishes to persist in the face of nonnative fishes. We conclude that a multiplicity of tools, techniques, and education remain important if we are to benefit and maintain our native fish fauna. 14:00 Ghosts of Our Making: Extinct Aquatic Species of the North American Desert Region Jack Williams 1, Don Sada 2 (1-Trout Unlimited, United States; 2-Desert Research Institute, United States) One of the primary priorities of conservation is to prevent extinctions. Thirty-three fishes and 23 aquatic invertebrates are recorded as recently extinct within the desert and adjacent regions of the United States and Mexico. Additionally, five fishes are listed as extinct in the wild. The process of extinction often begins with habitat degradation or other disturbance that diminishes local populations or causes local extirpations that lead to the entire species or subspecies being more susceptible to loss. Extinction itself is often linked to some catastrophic change in water supply, such as water diversion or spring failure due to over withdrawal of groundwater. Introductions of nonnative species that may prey on, compete with, or hybridize with native species, are more common in extinction of desert fishes than for aquatic invertebrates. Increasing numbers of endangered and extinct species are a cautionary account about our own future. The question for humans is whether the warning signs will be obeyed or whether society proceeds headlong into a future where our own species may be at risk. 14:15 The Value of Specimen Collections for Conserving Biodiversity Adam E. Cohen 1, Dean A. Hendrickson 1, Gary Garrett 1 (1-Biodiversity Center, Dept. Integrative Biology, University of Texas at Austin, United States) Specimen collections are critically important for modern ecological, evolutionary, and biogeographical studies and are increasingly aiding in conservation decision-making. The information collections contain in the form of specimen-backed occurrences, field notes and images can provide insights and guidance for researchers and resource managers, and serve as a verifiable base-line representing historical conditions. The Fishes of Texas Project is a regional, quality-controlled, database of museum specimens compiled from many collections and an online user interface allowing users to view, map and download data. It has enhanced conservation decision-making for aquatic species in Texas and might serve as a template for similar regional projects. 14:30 The Devils Hole Pupfish: Science in a Time of Crisis Mark Hausner 1, Kevin Wilson 2, Kevin Brown 3 (1-Desert Research Institute, United States;

12 2-National Park Service, United States; 3-University of California Santa Barbara, United States) The preservation of the Devils Hole ecosystem and the recovery of the Devils Hole Pupfish (Cyprinodon diabolis) was a great success story for the Desert Fishes Council and for the scientists and resource managers involved in the conservation efforts. Battle Against Extinction described the collaborative ecosystem-level research that led to the Supreme Court decision setting a minimum water level in Devils Hole. This minimum water level reflected the best available scientific information at the time, and as the water level in Devils Hole recovered the C. diabolis population tracked that recovery closely. As the C. diabolis population appeared to stabilize through the 1980s and early 1990s, ecosystem-level monitoring in Devils Hole was phased out in favor of other priorities. The lack of contemporary data, however, left resource managers unprepared to proactively address the unexpected and unexplained decline in the C. diabolis population that began in the mid-1990s. This decline became an existential crisis in 2006, when a spring survey counted just 38 individuals, and again in spring 2013 with a survey of just 35 fish. In this talk, we review the responses of both scientists and resource managers to these crises, as well as the role played by scientific research in formulating management responses. In 2006, most of the research on the Devils Hole ecosystem was years old, and the lack of current knowledge hampered the management response to the critically low population survey. The 2006 survey, though, spurred further research in the ecosystem, and the management response to the 2013 survey was both better informed and more effective than the 2006 response. Using Devils Hole as a case study, we argue that research into threatened and endangered ecosystems even when they appear to be stable is critical to the management and conservation of these resources. 14:45 Long-Term Monitoring of a Desert Fish Population Aravaipa Creek, Arizona Peter Reinthal 1, Heidi Blasius 2, Mark Haberstich 3 (1-University of Arizona, United States; 2-Bureau of Land Management, United States; 3-The Nature Conservancy, United States) Since the publication of Battle Against Extinction in 1991 there have been substantial changes to the natural and anthropogenic landscapes of the desert southwest. Environmental impacts have accelerated with increasing human populations but, unfortunately, scant attention is given to long-term changes in natural aquatic biotas. Beginning in 1963, W.L. Minckley, colleagues, and students monitored and studied fish assemblages of Aravaipa Creek, Arizona. Minckley s monitoring efforts continued until his death in 2001 and since then by the authors of this chapter. This represents the longest continuous record of abundance and distribution of any fish assemblage in the region. Considerable scientific information has been gained from these efforts and forms the basis for much that is known about several iconic native desert fishes. These data provide a comparative baseline to characterize responses to biotic and abiotic events and modifications of Aravaipa Creek. Data obtained provide critical information on fish assemblage dynamics, species ecology, impacts of human-induced alterations and management, and insights on potential consequences of global warming. Herein we present results from 54 years of Aravaipa Creek fish monitoring and illustrate how fish populations respond to changes in the Aravaipa catchment.

13 15:00 Conservation and the Historical Distribution of Gila Trout David Propst 1, Thomas Turner 1, Jerry Monzingo 2, James Brooks 3, Dustin Myers 2 (1- University of New Mexico; 2-Gila National Forest, USDA Forest Service; 3-JEB Outfitters) Restoration of a species to historically occupied habitats is a common conservation strategy, especially for interior North American salmonids. An essential early, if not first, step is to determine the historical range of target organism. For many southwestern fishes this has proven difficult as historical habitats were compromised or destroyed by European settlers before scientific investigations catalogued the native fauna of the region. Further complicating accurate delineation of native ranges were paucity of historical collections, introduction of nonnative species, and the shifting taxonomic designations of remnant populations. Following its description in 1950, Gila Trout Oncorhynchus gilae was the presumptive native trout of the entire Gila River drainage in New Mexico and Arizona. But the description of Apache Trout O. apache from a Gila River tributary in 1972 interjected uncertainty to the historical range of Gila Trout. Was Gila Trout limited to the upper Gila River in New Mexico and were the native trout of the Agua Fria and Verde drainages taxonomically distinct from Gila Trout? Absence of uncompromised specimens from Arizona streams precludes definitive resolution of this question, but historical accounts and several museum specimens support a close affinity of these populations with Gila Trout. Consequently, Gila Trout conservation efforts should continue to include its restoration to suitable habitats throughout the Gila River drainage, exclusive of Apache Trout streams. 15:15 Large-River Fish Conservation in the Colorado River Basin: Progress and Challenges with Endangered Razorback Sucker Kevin Bestgen 1, Thomas Dowling 2, Brandon Albrecht 3, Koreen Zelasko 1 (1-Larval Fish Laboratory, Colorado State University, United States; 2-Wayne State University, United States; 3- BIO-WEST, Inc., United States) Razorback Sucker Xyrauchen texanus, a historically widespread and abundant warmwater fish endemic to the Colorado River basin, has declined dramatically. Habitat alteration, dams that block migration routes and alter natural sediment, stream flow, and thermal regimes, channel change, and nonnative fish predation are reasons for decline of razorback sucker. Lack of recruitment was evident more than 50 years ago and all wild fish were eventually extirpated, with the possible exception of the small Lake Mead population. Extensive restoration efforts have had mixed outcomes. Various propagation programs have restored reproducing adults in lakes Mohave, Havasu, and Powell in downstream basin reaches, and the San Juan, Colorado, and Green rivers in the upper Colorado River basin. However, nonnative predators reduce survival of stocked fish and recruitment is non-existent except in Lake Mead. Localized recruitment in Lake Mead, and new strategies to enhance juvenile production in isolated lower Colorado River backwaters and connected Green River floodplain wetlands offer examples of recent successes. Further progress toward restoration of large-river fishes including Razorback Sucker requires additional flow, habitat, and nonnative fish management, and continued long-term support for conservation programs.

14 15:30 Politics, Imagination, Ideology, and the Realms of Our Possible Futures Christopher Norment (Department of Environmental Science and Ecology, College at Brockport, United States) The future of southwestern aquatic habitats and their native species is uncertain, due to possible impacts of climate-induced drought, population growth, and overutilization of scarce water resources, but also to politically and ideologically motivated attacks on the U. S. Endangered Species Act, and federal land management and regulatory authority. However, a potentially more profound danger is the development of a post-truth culture that accepts the notion of alternative facts and distrusts science. Such attitudes mean that the practice of science, as well as its findings, have political implications, a development that will make it difficult to develop effective approaches to counter likely, future droughts in the American Southwest, and consequent threats to regional aquatic biodiversity. Crafting a sustainable future for the Southwest and its native species and ecosystems will require a robust scientific understanding of the region s natural variability and system complexity, and advances in public policy and management. However, it also will require effective political action, and that a critical mass of people transcend blinding ideology, convention, and human short-sightedness. Finally, we must imagine the realms of our possible futures, and consider the historical context of past, present, and future efforts to protect regional aquatic biodiversity in the American Southwest. 15:45 Searching for Common Ground Between Life and Extinction Christopher Hoagstrom 1, Kevin Bestgen 2, David Propst 3, Jack Williams 4 (1-Weber State University, United States; 2-Colorado State University, United States; 3-University of New Mexico, United States; 4-Trout Unlimited, United States) Lineages of desert fishes that have persevered millions of years, through droughts exceeding any in the historical record, now collectively spiral toward extinction in the industrialized desert signaling the loss of functioning aquatic ecosystems. A century of large-scale water-resource development for agricultural and urban expansion has diminished these ecosystems to a point that exceeds prehistoric mega-droughts, although the accompanying climate is relatively wet. Anthropogenic habitat degradation and introductions of nonnative species exacerbate ecological depreciation. Persistent impacts create an ecological ratchet that now elevates extinction risks for remnant populations. Full restoration of natural habitats may be impossible today, but preservation and rehabilitation of remnant ecosystems and functions are critical. Collaborative approaches to reverse ratchet-like impacts could reduce extinction risks but need more public support and wider application. This is a wicked problem because resource managers face many limitations and require cooperation among numerous private and governmental organizations representing diverse values and priorities. Greater fusion of science, environmental ethics, and ecological economics could unveil common ground among stakeholders, which will be critical to forestall looming threats. 16:00-17:30 Session 3: General Session I (Chair: Kaleb Smith) 16:00 Feeding Ecology of Co-Occurring Early Life Stage Suckers in a Regulated River Casey Pennock 1, Michael Farrington 2, Keith Gido 1 (1-Kansas State University, United

15 States; 2-American Southwest Ichthyological Researchers L.L.C., United States) Survival of early life stage fish is affected by multiple factors including environmental conditions, biotic interactions, and starvation. Low survival of early life stage Razorback Sucker, Xyrauchen texanus, in the San Juan River, NM & UT is thought to cause a recruitment bottleneck. Conversely, two other native sucker species, Flannelmouth Sucker, Catostomus latipinnis, and Bluehead Sucker, C. discolobus, recruit to adulthood successfully. To explore a potential factor leading to this discrepancy among species survival, we used museum specimens collected from the San Juan River in 2007 to investigate diets of co-occurring early life-stage (< 30 mm SL) Bluehead, Flannelmouth, and Razorback Sucker. We evaluated both the diversity of diet (number of diet categories) and frequency of occurrence of different diet items. Bluehead and Flannelmouth Sucker did not differ in diet diversity, but on average had 40% and 42%, respectively, more diverse diet compared to Razorback Sucker. Discriminant function analysis (DFA) correctly classified species by frequency of occurrence of diet items 65% of the time, and accuracy varied among species. A low frequency of occurrence of most diet items in Razorback Sucker drove most of the variation (76%) explained by DFA. Razorback Sucker might be less efficient foragers compared to Bluehead and Flannelmouth Sucker. The lack of some diet items (i.e., sand, adult diptera) from Razorback Sucker diets suggests more constrained diet and potential habitat differences compared to other sucker species. Findings from this study shed light on differences in feeding ecology among species that have potential to influence success of early life stages through resource use or predation mechanisms. 16:15 Laboratory Experiments to Determine Effectiveness of Light Traps to Detect Razorback Sucker Larvae Catherine Devlaming 1, Kevin Bestgen 2 (1-Colorado State University, United States; 2- Larval Fish Laboratory, Dept. of Fish, Wildlife, and Conservation Biology, United States) Detection of endangered Razorback Sucker Xyrauchen texanus larvae by light traps is used to prompt flow releases to inundate Green River floodplain wetlands, habitat which may increase survival of those early life stages. However, little is known about the efficacy of light traps to capture or retain larvae. In the laboratory, we investigated effects of light trap set time, release distance from trap, light presence, and turbidity on capture and retention rates of four early life stages of Razorback Sucker. Mean capture rates of protolarvae prior to the development of a swim bladder (7-9 mm total length [TL]) was 40% (28-55%) over the various treatment effects, but rose to 76% (73-80%) after protolarvae formed a swim bladder (9-10 mm TL). Mesolarvae (11-17 mm TL), the most commonly captured life stage in field sampling, had similar mean capture rates as later protolarvae at 86% (82-90%). Capture rates of metalarval (mean = 42%, range 21-63%; mm TL) and juvenile (mean = 24%, range 20-28%; mm TL) life stages were lower. Retention rates were generally > 75% and increased to 97% for juveniles. The relationship between set time and distances of 1-5 m on capture indicated longer set times positively influenced capture rates while distance had little effect. Light traps may be a useful gear to detect first presence of Razorback Sucker larvae in riverine backwaters each spring, timing of which is used to begin high flow releases from Flaming Gorge Dam to

16 inundate Green River, Utah, floodplain wetlands. 16:30 The Influence of Groundwater Fluctuations on the Distribution and Habitat Associations of Two Cyprinid Fishes in a Desert Spring Complex Mark Grover 1, Chris Crockett 2 (1-Arizona Game & Fish Department, United States; 2- Utah Division of Wildlife Resources, United States) Relationships between temporal variation in groundwater levels and the distribution and habitat use of two cyprinid fishes, Least Chub (Iotichthys phlegethontis) and Utah Chub (Gila atraria), were examined at a spring complex (Leland Harris Spring Complex) in the Snake Valley of the Great Basin, Utah, USA in which groundwater has been monitored since Seasonal declines in shallow groundwater were associated with protracted periods of high evapotranspiration during Temporal changes in groundwater levels explained 97% of the variation in the mean values of surface water levels obtained from measurements taken over a three-year period at 47 monitoring points. Bathymetric data, combined with data from surface water monitoring, indicated that the volume of surface water present in springs and spring-fed ponds when groundwater levels were at their lowest was only 19% of the volume of water present during peak groundwater levels. Visual and minnow trap surveys indicated that Least Chub and Utah Chub were usually associated with relatively deep water, but migrated annually from deep springs to ponds, which were used as spawning and juvenile habitat, when groundwater and surface water levels were high, returning to core spring habitats as ponds receded during the late summer and early fall. Populations of both species became increasingly fragmented as groundwater and surface water levels declined. Least Chub and Utah Chub tended to use the same core habitats from one year to the next during the late summer and fall, and were positively associated at both the habitat and microhabitat level. The strong relationship between surface water and groundwater levels, and the dependence of Least Chub and Utah Chub on seasonal expansion of lentic habitats for reproduction, indicate that predicted reductions in groundwater levels resulting from proposed groundwater withdrawal projects would eliminate most of the spawning and juvenile habitat in the spring complex. 16:45 Fine-Scale Analysis of Population Structure in the Relict Dace Using RAD Sequencing Mandi Finger 1, Alyssa Benjamin 1 (1-University of California, Davis, United States) We have examined the population structure and diversity of relict dace within Goshute, Butte, Steptoe, Spring, and Ruby valleys in eastern Nevada. We used RAD sequencing on our samples, a method of interrogating the entire genome of each individual. Our results concur with the recent Housten et al. (2015) paper, in that there is a major split within the relict dace range: Ruby and Butte valleys are similar, and Goshute, Steptoe, and Spring valleys are similar. However this is relative, because nearly all populations are highly distinct within the valleys. We will discuss our results and provide recommendations for management. 17:00 Hope in a Highly Regulated River: Native Fish Recovery in the Colorado River David L. Rogowski 1, Jan K. Boyer 1 (1-Arizona Game and Fish Department, United States)

17 In many rivers altered by dams, native fishes have been extirpated or persist at small fractions of their original abundance and distribution, despite extensive recovery programs. The Colorado River is one of the most regulated rivers in the world, and native fish populations in the Colorado River basin have declined due to threats from invasive species and habitat change (e. g., dams, water diversions). However, over the past 19 years within the Grand Canyon, native fishes have increased in abundance and expanded their ranges in the highly regulated Colorado River. We used data from a long term monitoring program ( ) to describe changes in native and nonnative fish abundance and spatial distribution. Fish were sampled using boat electrofishing and baited hoop nets at randomly selected sites (stratified by ~ 8km reaches) between Glen Canyon Dam and Lake Mead ( river kilometers). Catch per unit effort was calculated as an index of relative abundance. Native fishes increased in abundance during the study period; conversely most non-native species decreased in abundance. Non-native species comprise most of the species assemblage in cold tailwater habitat between Glen Canyon Dam and the Little Colorado River Confluence, but downstream of the Little Colorado River, native fish outnumber non-native fish. Western (downstream) reaches of the Grand Canyon appear to provide particularly important habitat for native fish. Native fishes increased in abundance with increasing river mile, and most age-1 and younger fish were captured in western Grand Canyon. We hypothesize that a combination of an increasing amount of riverine habitat as Lake Mead recedes, tributary refugia, impediments to establishment of warmwater predators, and modifications to Glen Canyon Dam operations, has contributed to the native fish recovery observed in the Colorado River in Grand Canyon. 17:15 Efficacy of Mechanical Removal of Nonnative Fish from Closed Systems. an Update on Bonita and Aravaipa Creeks Heidi Blasius 1, Jeff Conn 2 (1-Bureau of Land Management, Safford Field Office, United States; 2-Desert Fish Advocate, United States) Bonita and Aravaipa Creeks are located within southeastern Arizona and are unique in that they still support intact native fish assemblages and exceptional riparian and aquatic values. Past native fish recovery actions, including construction of fish barriers that prevent or hinder future upstream incursions of nonnative fishes from downstream sources, have benefitted both creeks. However, both native fisheries are still threatened by the presence of nonnative predatory and competitive fish species. To reduce the threat of nonnative fishes in both systems, the BLM, Safford Field Office, collaborated with federal, state, private, and non-governmental partners to begin mechanical removal of Green Sunfish in 2009 at Bonita Creek and 2010 at Horse Camp Canyon, Aravaipa Creek. Green Sunfish were targeted due to their highly piscivorous nature and their ability to thrive in these two systems. In Bonita Creek, nonnative fishes were removed from a 1.9 mile reach dominated by beaver dam pools and glides. Beaver dams effectively reduce the movement of green sunfish within the removal area. In Horse Camp Canyon, nonnative fishes were removed from a 0.5 mile reach that is characterized by boulder-strewn bedrock pools and slots. Boulders and other natural features restrict movement of fish into the removal reach of Horse Camp Canyon except during seasonal flood events when a surface connection exists to Aravaipa Creek. Baited Gee metal minnow traps, collapsible Promar traps, and hoop nets were the primary removal methods used at both creeks. Occasionally seines, dip nets, and backpack electrofishers were used to augment and assess efforts.